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From:Dima Chernyshenko Date:April 1 1999 6:43am
Subject:multiple table joins, speed question
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I have got a database with the following structure:
table attribs: num int, ... (other fields)
table facts: num int, fact int
table objects: num int, object int 

The table attribs contains about 3400 entries, 'num' is the primary key
(i.e. all num's are unique). The tables facts and objects contain about
16000 entries each, around 5 entries for each value of 'num'. What i need
is to do a query like:

select attribs.num from attribs,facts,objects where
  attribs.num = facts.num and attribs.num = objects.num and 
  fact in (1,2,4,6) and
  object in (2,67)

And though the tables are quite small, this query takes too much time
(over 2 seconds). In fact I've got 2 more databases, when I try to join
all 5, it takes forever to finish, while MS Access can execute all those
queries in 1-2 seconds. Maybe someone can give advice how to optimize the
queries/reorganize the structure to get the optimal performance? 

Dima Chernyshenko

multiple table joins, speed questionDima Chernyshenko1 Apr
  • Re: multiple table joins, speed questionChristian Mack1 Apr